* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.container {
    width: 870px;
    margin: auto;
}

.container::after {
    content: "";
    display: table;
    clear: both;
}

header {
    background: #61bae6;
}

nav {
    padding-top: 11px;
    padding-bottom: 11px;
}

nav .nav-left,
nav .nav-center,
nav .nav-right {
    float: left;
    width: 33.333333%;
}

nav .nav-left {
    height: 56px;
}

nav .nav-center {
    text-align: center;
}

nav .nav-right {
    text-align: right;

}

nav .nav-right a {
    color: #fff;
    font-size: 12px;
    font-weight: bold;
    text-decoration: none;
}

nav .nav-right a img {
    display: none;
}

/*banner部分的样式*/
.banner .col {
    width: 50%;
    float: left;
}

.banner {
    color: #fff;
    margin-bottom: 60px;
}

.banner p {
    font-weight: bold;
}

.banner h1 {
    font-weight: 300;
    margin-bottom: 25px;
    font-size: 36px;
}

.banner a {
    background-color: #2996cc;
    padding: 15px 53px;
    font-weight: bold;
    text-decoration: none;
    color: #fff;
    font-size: 12px;
    display: inline-block;
    border-radius: 2px;
    transition: .5s;
}

.banner a:hover {
    background-color: #1882b7;
}

.banner img {
    width: 100%;
    display: block;
}

/*页面的主体部分*/
main {
    margin-bottom: 60px;
}

main .col {
    width: 25%;
    float: left;
    text-align: center;
    padding-left: 10px;
    padding-right: 10px;
}

main img {
    margin-bottom: 10px;
}

main h3 {
    font-size: 14px;
    margin-bottom: 10px;
}

main p {
    font-size: 14px;
    color: #657082;
}

/*首页的下载部分*/
.download {
    border-top: 1px solid #e0e0e0;
    text-align: center;
    margin-top: 65px;
    margin-bottom: 65px;
    padding-top: 65px;
}

.download h2 {
    margin-bottom: 20px;
}

.download p {
    margin-bottom: 35px;
}

.download a {
    display: inline-block;
}

.download img {
    margin-bottom: 0;
}

/*底部样式*/

footer {
    background-color: #1b2126;
    color: #6a777d;
    padding-top: 60px;
    padding-bottom: 60px;
}

/*响应式的代码*/
@media (max-width: 600px) {
    .container {
        width: 80%;
    }
    /*登录按钮的响应式*/
    .nav-right span {
        display: none;
    }
    nav .nav-right a img {
        display: inline-block;
        margin-right: 30px;
    }
    /*banner部分的样式*/
    .banner .col {
        width: 100%;
        text-align: center;
    }
    .banner a {
        margin-bottom: 30px;
    }
    .banner img {
        width: 80%;
    }
    
    /*主体部分*/
    main .col{
        width: 100%;
    }
}
